From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id 5D01E8D0040 for ; Thu, 31 Mar 2011 15:26:53 -0400 (EDT) Date: Thu, 31 Mar 2011 15:26:50 -0400 From: Steven Rostedt Subject: Re: [PATCH 05/12] mm: alloc_contig_range() added Message-ID: <20110331192650.GE14441@home.goodmis.org> References: <1301577368-16095-1-git-send-email-m.szyprowski@samsung.com> <1301577368-16095-6-git-send-email-m.szyprowski@samsung.com> <1301587361.31087.1040.camel@nimitz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1301587361.31087.1040.camel@nimitz> Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: Marek Szyprowski , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org, linux-mm@kvack.org, Michal Nazarewicz , Kyungmin Park , Andrew Morton , KAMEZAWA Hiroyuki , Ankita Garg , Daniel Walker , Johan MOSSBERG , Mel Gorman , Pawel Osciak On Thu, Mar 31, 2011 at 09:02:41AM -0700, Dave Hansen wrote: > On Thu, 2011-03-31 at 15:16 +0200, Marek Szyprowski wrote: > > + ret = 0; > > + while (!PageBuddy(pfn_to_page(start & (~0UL << ret)))) > > + if (WARN_ON(++ret >= MAX_ORDER)) > > + return -EINVAL; > > Holy cow, that's dense. Is there really no more straightforward way to > do that? > > In any case, please pull the ++ret bit out of the WARN_ON(). Some > people like to do: > > #define WARN_ON(...) do{}while(0) > > to save space on some systems. That should be fixed, as the if (WARN_ON()) has become a standard in most of the kernel. Removing WARN_ON() should be: #define WARN_ON(x) ({0;}) But I agree, that there should be no "side effects" inside a WARN_ON(), which that "++ret" is definitely one. -- Steve -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org